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Topic: Catalytic convertor issues (Read 2395 times)

- lack of power at low rev- black smoke come out of the exhaust just after start up the engine when its cold, last about 20 seconds then disappear- Heaps of carbon built up on the throttle body, found out about this when I was cleaning it last week

From all above, I think cats are blocked

The car has done almost 180k and has got straight through mufflers modified, I know the straight through mufflers have no back pressure so it can be powerless at low rev but I think its going worse and worse now, it wasn't this bad when I first modified it

I am thinking to get the cats replaced with resonators, but worrying about the sound, will it get a lot nosier? and can you guys confirm if all the symptoms leads to catalytic convertor failure?

I'd say do a full intake clean out, the EGR system on them builds up alot of carbon from the AFM right to the valves.

I done mine and blanked of the EGR, so i dont get any carbon. This is my intake after i acid tanked the bottom and steam blasted the top

i should of taken some before photo's, but it looked something like this.

Cause the cold start the EGR is reusing the rich exhaust gas it'd be going round a few times in the dirty intake.

Its had a good regular service history. but the other issue these motors have are the EVTC spring washers binding up. Russia's have a huge problem with these in the winter and they will smoke and idle rough like a tractor. Mine are rattling at the moment under low rpm and low load. but i dont think this is your problemAnother issue these motors have are the cam sensors will burn out over time, bein at the rear of the heads they are in the heat of the motor with no air flow. and will start to cause firing and vtc issues. The final one which hopefully with your regular servicing you might get away with is the primary cam chain stretch. nissan claim theyre not meant to, but i've heard of 4 m35's from 180km-my 280 km motors.

N/A engines will tend to be louder than when restricted by a turbo and resonators may be more noisy than your catalytic converters. These do wear out and clog up so you could consider getting a pair like mine ( I have just one of the 100 cpsi models but he does a good price for a pair):http://www.venomexhaustworks.com.au/products.html#